Help - Whining noise when accelerating (Solved)

[NeilH]

Hi All.

*Urgent*

Bmw z3 1.9 16v 1998

Is it safe to drive my car without causing damage. When im accelerating the car pulls fine changes gear fine, steers fine. However it makes a fairly loud whining noise when i accelerate.

I can only describe it sounding like a car reversing at very high speed (that sound) it drops off when i stop accelerating.

Any ideas and is it safe? Ive read.

Alternator
Tensioner pulleys
Belts
Water pump

I dont want have replace all unless needed.

I wont be able get it to a garage for a few weeks now with christmas etc.

Many thanks

Neil.

 

[Eddie Zedder]

I get a whining noise when accelerating as well, it always stops when I leave the wife at home .

 

[NeilH]

I like that suggestion for a cheap fix lol

 

[Stevo7682]

I get a whining when accelerating as well, it always stops when I leave the wife at home .

Got to say when I read the thread title it was also my first thought but you beat me to it.
Stephen.

 

[Stevo7682]

Is the noise only present when moving or is it there when you rev up engine.
Stephen

 

[NeilH]

Haha. I believe its just when im moving but il find out. Dont want annoy the neighbours too much revving on the drive but il do a test asap. Does it make a lot of difference to what the issue? It sounds mechanical if that helps. Not exhaust im pretty sure, that is noisy but think thats the catalyic converter on way out.

 

[Toby]

Got to say when I read the thread title it was also my first thought but you beat me to it.
Stephen.

me too

 

[Stevo7682]

Big paragraph coming ( once I take the 20 minutes to write it out on my phone )
Stephen.

 

[Stevo7682]

Let's break it down first.
Do as I already asked if only when moving is if if does it when you aren't moving you can rule a ton of stuff out straight away .
If you rev the engine blip throttle etc and the noise is there it could still a few things .
If you turn the steering lock to lock and the noise becomes apparent check the power steering level .
If this makes no difference but revving can be heard could be the water pump, alternator or similar next step would be to remove the drive belt and spin all the auxiliary components by gand looking for play and noise and roughness
As with all zeds check for split vacuum pipes and hoses .

Now if the noise only when you are driving this brings a whole host of new things into play.
First thing is to pinpoint what creates the noise ie .
What speed creates the noise ,does rocking steering or going round corners change the tone, is it the same in gear or neutral ( assuming it's a manual)
.
Can you pinpoint where the noise originates from does it happen only when on the gas in any gear like if you were doing 40 in 4th and it whines on the gas and not off it or vice versa could be rear diff or gear box if only at speed then could be wheel bearing ( jack up the corner you think spin the wheel looking for roughness noise and vibration
Does going on and off brake change the noise ?

There's a few things to maybe help really need a bit more information to help you with out it much more without seeing the car or seeing a video of the nose when it doing it.

Stephen.

 

[NeilH]

Thank you very much for all that.

I dont have tools or mechanical knowledge do some of them things but i can start to do the tests to start eliminating things and then at least im going to the garage with some knowledge. Its finding a decent garage thats an issue as well. One ive been going for years is always too busy so i tried another and unsure on them at the moment...

Il start with the basics -

First test rev it up on the drive tomorrow in between doing work

2nd turn the steering lock to lock listen out for the noise check power steering fluid level

and il report back

 

[NeilH]

About hearing the noise when im driving. Yes its a manual.

It seems to be any gear and starts fairly low in the rev range and gets louder as the revs go up (noise kinda like a car reversing faster and faster as i rev more) il have to listen out if any different when turning at speed. It only whines when on gas. (I had a new rear diff bush fitted not long ago could that be an issue?)

I can jack the car up and spin the wheels at somepoint check for sounds etc and brake test it just doesnt sound bearing or wheel related.

Thanks

 

[IanA]

Viscous fan coupling.

 

[t-tony]

I get a whining noise when accelerating as well, it always stops when I leave the wife at home .

Bugger, beat me to it Bryan.

Tony.

 

[Pingu]

My thought is the diff.

If it is, it will be most noticeable in top gear on the motorway. You can make the noise stop by having the engine match the car with just the right amount of power for that speed. Too little and it whines, too much and it whines. The speed doesn't matter, it's whether the car is being "pushed" by the engine, or "held back" by the engine.

 

[t-tony]

Try removing the drive belt and see if the noise goes away. Cold weather is a good time to try this. Does the noise appear without driving the car, or does it not happen while stationary ?

Tony.

 

[NeilH]

So first few checks done and some pics albeit it not gr8.

Test 1 - Does it make the same noise when stationary?

Well whilst it was colder i thought i heard it. Starting at 3k rpm and continuing upto redline. Then when it got a little warmer i couldnt really hear the sound and nothing at all just on idling.

Test 2 - Turning the wheel full lock and to either side.

If held and full lock it makes a whirring noise? But i think all cars do that if held at lock and doesnt quite sound the same noise. (There is a small noise from the steering wheel itself inside cabin but think its plastic catching behind the wheel)

Test 3 - power steering fluid check.

Level looks good

 

[NeilH]

Whats next guys? Take to garage get that belt done and tensioners checked? Save for the zed shed but still safe to use??

Rubber Hoses - btw cant see or feel any tears or holes/rips but may be underneath some ive not seen would need do a better check with more time

And thanks

 

[MisterP007]

Bugger, beat me to it Bryan.

Tony.

Leave SWMBO at home was my first thought as well! In my case, the whining noise also gets louder when the car hits 3000 rpm and the DISA opens. Whining goes:

"1000-2000 rpm eeeee, eeeeee, eeeeee, 3000 rpm ayyeeeeeeeeeeeee, 5000-7200 rpm Jesus Christ, we are going to die!" Does this sound familiar? If it does not sound like this above 3000 rpm then you need to change the 2.8 manifold and DISA to a 3.0 version, cold air intake and a decent free flow exhaust"

As for the real answer listen to @Stevo7682

 

[Rudyrov]

A long shot, have you checked for alternator whine through the stereo? This is a condition caused by a "ground loop" in the radios electrical circuit as is also described as a whine that parallels RPM. It is usually only audible when the radio is turned on.
As I said, a long shot but perhaps worth mentioning.

 

[NeilH]

Any suggestions welcome cheers. I dont have the radio on very often at all and it makes the sound with it switched off. Thanks.